A method for assessing resistance-welded joints is made known in German Patent Application DE-A 43 25 878. In order to assess welds during the welding process itself, the ultrasonic permeability, or attenuation, of the welded joint is determined by acting upon said welded joint with shear waves. To accomplish this, the mean ultrasonic energy is determined from the output signal from the ultrasound receiver during each current half-cycle of the welding current within a time window that is delayed relative to the constant ultrasonic transmitted signal by a defined delay time. The mean ultrasonic energy is used as a measure of the quality of the welded joint. How the time window is selected and the time interval by which it should be delayed relative to the ultrasonic transmitted signal are left open, however.
The object of the present invention is to provide a device that allows the measurement window to be automatically adapted to different measurement situations.